package day2;

/**
 * @author oldliu
 * @since 1.0
 */
public class StrTest5 {
    public static void main(String[] args) {
//        String s="   aa bbb   ";
//        s=s.trim();
//        System.out.println(s);
        String s2="dog is our friends";
        String s3 = s2.replace("o", "ff");
        System.out.println(s3);
    }
}
